There are basically 2 types of welding machines. The DC welder and the AC welder. For the sake of what we will be concentrating on in this article, the DC welding machine is the most common of the 2 types. When TIG welding, straight polarity (DCEN) is used. When setting up the machine for TIG the electrode or torch should be connected to the negative terminal of the welder. This will result in a cooler weld temperature at the material to be welded.
Another option that is very helpful, although not necessary is a foot pedal remote amperage control. This foot pedal not only controls the amperage from zero to a preselected high amperage, but also activates the High Frequency arc start and gas flow. If you happen to have an older DC machine that was designed primarily for stick welding, you do not have the remote options, High Frequency start, or gas control.
However, if this is all you have, this machine will work fine. Years ago, we used old DC generator type machines to TIG weld without any problems. The disadvantage was having to manually turn on the gas flow from the torch by means of a gas control knob, and scratch starting the arc which meant a highly likelihood of tungsten contamination in critical X-ray quality welds. This may not pose a real problem for simple welding applications but if there is a concern, a scratch plate to start the arc can be used.
With the advent of new technologies, the inverter type welder is an excellent choice for welders, because of their light weight, (40lbs or less!) portability, and dual voltage (115v or 220v). They all feature remote control, HF (high frequency) arc start, and shielding gas control which includes post flow gas timer control. Since I’m not in the business of selling welding machines, I won’t go through the list of impressive features on this Miller unit.
This unit is one of the commonly seen “Made somewhere over there” units that claim 3 in 1 capabilities…TIG, Stick, and Plasma cutting. A friend of mine recently purchased this model and asked me to evaluate it’s performance. Well, I don’t know if I would carry this machine to a Union job site, but to my surprise it worked remarkably well for a under $500.00 machine! Plugged into a standard wall outlet, the TIG process, along with the remote function and post gas control did an impressive job. The plasma cutting was equally impressive, and at 35lbs, very portable…so for the cost, this may be the way to go for the budget minded…
